<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <script src="https://unpkg.com/vue@3/dist/vue.global.js"></script>
</head>
<body>
  <div id="app"></div>
  <template id="demo">
    <div>
      <h2>{{state.title}}</h2>
      <h3>{{state.count}}</h3>
      <button @click="decrement">-1</button>
      <button @click="add">+1</button>
    </div>
  </template>

  <template id="bot">
    <div>BOT page</div>
  </template>

  <script>
    const { createApp, reactive } = Vue
    const app = createApp({
      template: '#bot',
      setup() {
        let state = reactive({
          title: 'Hello World',
          count: 0
        })

        const decrement = () => {
          state.count--
        }
        const add = () => {
          state.count++
        }

        return {
          state,
          decrement,
          add
        }
      }          
    })
    app.mount('#app')
  </script>
</body>
</html>